Well, first of all, EVERY physical quantity is measured in a combination
of 2 or more units, except for mass, length, time, and electric charge.
ALL other units are made out of these. So it should not surprise you.
[ Example: Speed = (length) / (time) ]
Density is not the mass of a substance. It's the mass of a substance in
a standard volume of it. So the density is made of the mass in any lump
and the volume of that lump. That way, no matter how much of a substance
you have, you can always compare the lump you have to all other substances.
Surveys are considered the most reliable way to gather data
Question
What was the change in potential energy of the sheep?
Answer:
1962(m) J
Explanation:
Potential energy is given by
PE=mgh
Change in potential energy is given by
∆PE=mg(h2-h1)
Where ∆PE is the change in potential eneegy, g is acceleration due to gravity, h2 is final height and h1 is the initial height.
Substituting 9.81 m/s² for g, 1200 m for h2 and 1000 m for h1 then
∆PE=m*9.81(1200-1000)=1962m Joules
Since we are not given the mass of rhe sheep, the answer will be 1962(m) Joules
